Field of the Invention
The present invention relates to a method for performing an inventory of the hardware components connected to a control unit test system, wherein control units can be tested with the test system in an environment simulated by the test system by means of a model, and wherein the test system comprises at least one computer and hardware components that are connected to one another by means of at least one network.
Description of the Background Art
Test systems for performing control unit tests are known in the prior art. For example, control units for motor vehicles can be tested, as well as control units for other devices such as, e.g., automated production equipment such as robots, or even for other transport means, as for example airplanes. All of these devices have largely in common that, in order to function in an error-free manner, they have at least one control unit that acquires environmental data, or data from sensors interacting with the environment, and responds thereto.
In order to verify the (error-free) functioning of control units, a method is used that is also called “hardware-in-the-loop” and in essence dictates that an actual existing electronic control unit is tested, for which purpose this control unit is integrated into a test system that includes at least one computer that simulates a test environment, for example with the aid of a model that is stored and executed therein, and also includes additional hardware components that are connected to one another for the purpose of communication, which can take place, for example, via at least one network, in particular a network designed as a bus.
Examples of typical hardware components, which includes the control unit to be tested itself, include cable harnesses, mechatronic components, actual loads, as well as other electronics required to perform an individual test, for example A/D converters, interfaces, etc.
Especially by means of actual loads, it is possible to take into account in a test that is to be performed that under some circumstances certain environmental conditions, such as external influences on a control unit, may not be provided by a model in a simulation; consequently, in such a case actual, real loads are connected to the test system, for example actuators, sensors, or other data generators, especially actual hardware components of a system into which a control unit is incorporated for its later operation.
One concrete example from the motor vehicle field is the attachment of a throttle valve to the test system, since this component exhibits a behavior that is difficult to impossible to capture in simulation. Other actual loads, such as a steering system or a gas, brake, or clutch pedal, for example, can likewise be connected, even if they are simulatable in principle.
A concrete test can provide, for example, that the inputs of a control unit are simulated with sensor data from a model, or alternatively, if such sensor data cannot be obtained from a model by simulation, are simulated through data from the aforementioned real components.
The reaction to such data by a control unit to be tested can be accomplished by reading back output data of the control unit into the model or the computer executing the model and can thus be checked, which is to say tested. It is an advantage that such a test system can simulate an environment for the control unit to be tested essentially in real time, so that the control unit can be tested as though it were actually installed in the device in which it is intended to be used later. In order to permit real time capability, simulation cycles can have a preferred duration of less than 1 ms.
Potential errors in a control unit can be detected early by means of such a test system, in particular can be reproduced through repetitive simulation sequences, and the correction of discovered errors can be verified, in particular through repetition of the test sequences that led to the error.
It is critical to the error-free function of a test system that the configuration of the test system has also been performed correctly. Such a configuration, which is to say the assembling of the individual hardware components of the test system, is performed largely manually, with the result that susceptibility to errors of the test system itself also results from incorrect hardware components having been integrated in the test system during configuration.
For example, if a certain test, which is to say a certain environmental condition or interaction of a control unit with the simulated environment, is to be tested, an error can be caused simply by the fact that a hardware component is selected that is not suitable for providing the desired environmental condition to be simulated.
For example, if a throttle valve controller for a 6-cylinder engine that is implemented in a control unit is to be tested by means of a test system, it is evident that this test cannot be performed correctly if a 4-cylinder throttle valve is inadvertently connected to the test system as the actual load by a human being configuring the test system.
The susceptibility to error of a manually configured test system can be reduced, for example, if an option is realized for performing an inventory of the hardware components connected to a control unit test system, because such an inventory allows information to be available at all times concerning the actual hardware components that are connected to the test system in question.
To date, any inventorying in the prior art merely provides for a manual compilation of the applicable components in a test system on the basis of the manual configuration of the individual hardware components in the test system. However, this, too, involves the risk of errors on account of the human influence. Moreover, manual compilation is time-consuming and cost-intensive.